Two water-soluble polysaccharides from mung bean skin: Physicochemical characterization, antioxidant and antibacterial activities

Two water-soluble polysaccharides were extracted and purified from mung bean (Vigna radiate) skin by cellulose-enzyme assisted extraction (MBP-1) and hot-water extraction (MBP-2), respectively. The physicochemical properties, antioxidant and antibacterial activities of MBP-1 and MBP-2 were investigated and compared. Results showed that MBP-1 and MBP-2 had different sugar, protein, and uronic acid contents. MBP-1 was consisted of rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), xylose (Xyl), mannose (Man), and galacturonic acid (GalA), MBP-2 was mainly composed of Rha, Ara, Gal, Glc, Xyl, fructose (Fru), and GalA, and with molecular weights (Mws) of 139 and 208 kDa, respectively. Thermal gravimetric analysis (TGA) suggested that MBP-2 had more a stable structure than MBP-1. Antioxidant assay showed that they all exhibited strong DPPH•, •OH and ABTS+• radicals scavenging abilities. MBP-1 and MBP-2 also exhibited moderate antibacterial activities against both Gram-positive (G+) and Gram-negative (G−) bacteria. [Display omitted] •Two mung bean skin polysaccharides were extracted by cellulose-enzyme assisted (MBP-1) and hot-water extraction (MBP-2).•MBP-1 and MBP-2 had strong radical scavenging ability.•MBP-1 and MBP-2 polysaccharides exhibited moderate antibacterial activities.